One step closer...

A tray for the battery was added. Keeping simplicity and light weight in mind, I have built this tray based on an aluminium foil and four threaded rods. Four plastic straws (from kids balloons) served as spacers between the tray and the quadcopter chassis. The height of the tray was set based on the Turnigy 5000 mAh 3S battery I will be using:

I have also attached the RX with these modern velcro tapes that mate with a surface of the same type (e.g. 3M Dual Lock). I have to say is one of my favorite materials in this hobby:

At this point of progress, the remaining steps are few: solder the missing bullet connectors between the motors and the ESCs, reflash the ESCs, attach these to the frame, do the electrical connections, adjust the flight controller, connect the props...and Bob's your uncle :)